Device for indexed adjusting a mobile part position

Abstract

A device for automatic indexed guidance of a moving part ( 53 ) guided about an axis of rotation ( 5 ) on a fixed part ( 1 ) that is fixed about said axis of rotation ( 5 ), the device comprising: a toothed element ( 40 ) mounted to rock about a rocking axis ( 41 ) substantially parallel to the axis of rotation ( 5 ); a ratchet ( 12 ) defining a plurality of abutments for the toothed element ( 40 ), said abutments being angularly disposed around the axis of rotation ( 5 ); and a cam path ( 10 ) for controlling the rocking movements of the toothed element ( 40 ) about its rocking axis ( 41 ) during rotation of the moving part; said device comprising a firs rigid one-piece fixed cheek-plate ( 1 ) provided with a plurality of staged surfaces defining: the ratchet ( 12 ); the cam path ( 10 ); and at least one bearing surface ( 13, 14 ) suitable for guiding a moving plate ( 57 ) in rotation about the axis of rotation ( 5 ), the moving plate supporting the rocking axis ( 41 ) of the toothed element ( 40 ).

What is claimed is:  
     
       1. A device for automatic indexed guidance of a moving part guided about an axis of rotation fixed part that is fixed about said axis of rotation, the device comprising: 
       a toothed element mounted to rock about a rocking axis substantially parallel to the axis of rotation;  
       a ratchet defining a plurality of abutments for the toothed element, said abutments being angularly disposed around the axis of rotation; and  
       a cam path for controlling rocking movements of the toothed element about its rocking axis during rotation of the moving part; and  
       a first rigid one-piece fixed cheek-plate provided with a plurality of staged surfaces defining  
       the ratchet,  
       the cam path, and  
       at least one bearing surface guiding a moving plate in rotation about the axis of rotation, the moving plate supporting the rocking axis of the toothed element.  
     
     
       2. A device for automatic indexed guidance of a moving part guided about an axis of rotation on a fixed part that is fixed about said axis of rotation, the device comprising: 
       a toothed element mounted to rock about a rocking axis substantially parallel to the axis of rotation;  
       a ratchet defining a plurality of abutments for the toothed element, said abutments being angularly disposed around the axis of rotation;  
       a cam path for controlling rocking movements of the toothed element about its rocking axis during rotation of the moving part; and  
       a first rigid one-piece fixed cheek-plate provided with a plurality of staged surfaces defining  
       the ratchet,  
       the cam path, and  
       at least one bearing surface guiding a moving plate in rotation about the axis of rotation, the moving plate supporting the rocking axis of the toothed element  
       and wherein the first fixed cheek-plate has a through hole about the axis of rotation enabling at least a portion of the shaft of the moving part to pass therethrough, the first fixed cheek-plate further comprising, starting from the axis of rotation and going radially outwards towards an outline of the first fixed cheek-plate: 
       a first bearing surface formed by a substantially transverse annular surface inwardly defined by the cylindrical edge of the through hole and outwardly defined by a cylindrical edge about the axis of rotation;  
       a substantially transverse wall forming a cheek wall of the first fixed cheek-plate;  
       a cam path formed by a surface extending substantially perpendicularly to the cheek wall;  
       a second substantially transverse bearing surface inwardly defined by the cam path and outwardly defined by a toothed ratchet that is annular about the axis of rotation;  
       a third substantially transverse bearing surface inwardly defined by the ratchet and outwardly defined by an annular wall about the axis of rotation; and  
       a fourth substantially transverse bearing surface inwardly defined by the annular wall and outwardly defined by the outline of the first fixed cheek plate.  
     
     
       3. A device according to  claim 2 , characterized in that the cam path comprises two half cam paths that are substantially symmetrical about a plane (T) perpendicular to the cheek wall of the first fixed cheek plate. 
     
     
       4. A device according to  claim 3 , further comprising: 
       a resilient part mounted on the first fixed cheek plate, said resilient part including an inclining surface causing the toothed element to rock so as to prevent the moving part from turning in one direction of rotation;  
       a moving plate in the form of a generally disk-shaped part provided:  
       with a through hole through which the shaft of the moving part passes; and  
       means for enabling the moving plate to be prevented from rotation relative to said rotary shaft;  
       the moving plate being also provided on a first transverse face with a stud defining the rocking axis of the toothed element;  
       the toothed element is a substantially planar part provided with:  
       an axial hole mounted on the stud of the moving plate;  
       a stud projecting from a transverse face, said stud forming a cam-follower finger for reading the cam path during rotating of the moving plate relative to the first fixed cheek-plate; and  
       teeth over at least a first side surface, said teeth being substantially complementary in shape to the teeth of the ratchet of the first fixed cheek-plate;  
       the toothed element is provided with an overall plane of symmetry (S), having first and second toothed surfaces disposed on an outer side surface of said toothed element;  
       the toothed element further includes a support part about the axis, the support part being mechanically linked to the moving plate so as to be rotated together therewith during movement of the shaft, said part supporting resilient return means for the toothed element;  
       the resilient return means is a flexible blade provided with an abutment, the toothed element being provided with an abutment of complementary shape such that said toothed element can occupy the following stable states:  
       a first state in which the first toothed surface of the toothed element bears against the ratchet of the first fixed cheek-plate;  
       a second state in which the toothed element is not in contact with the ratchet, said spacing apart being conserved by reversible locking of the abutment against the complementary profile of the resilient means; and  
       a third state in which the second toothed surface of the toothed element bears against the ratchet of the first fixed cheek-plate;  
       further comprising a second fixed cheek-plate provided with a through hole enabling the shaft of the moving part to pass therethrough, said second cheek-plate being suitable for being secured to the first fixed cheek-plate so as to form a box (BO) in which there is housed the rotary assembly constituted by:  
       the moving plate;  
       the toothed element that rocks on the moving plate about the axis; and  
       the support part for supporting the resilient return means;  
       the second fixed cheek-plate is snap-fastened onto the first fixed cheek-plate so as to retain said rotary assembly;  
       after the first and second fixed cheek-plates have been fixed together, the bearing surfaces of the first fixed cheek-plate serve as follows:  
       for the first bearing surface to guide the support part in rotation about the axis and to prevent the support part from moving in translation;  
       for the second bearing surface to bear against at least a portion of a transverse surface of the toothed element; and  
       for the third bearing surface to guide the moving plate in rotation about the axis and to prevent the moving plate from moving in translation;  
       the moving plate comprises a stud projecting from a transverse face placed facing the second fixed cheek-plate, the stud being received in a holding bearing surface formed in the second fixed cheek-plate, the stud constituting an abutment for actuating at least one resilient member contained in said bearing surface;  
       the holding bearing surface is an annular groove about the axis;  
       the holding bearing surface contains a first spring and a second spring, the second spring being stiffer than the first spring, at least one of the first spring and second spring co-operating with means suitable for limiting deformation of the first spring to a predetermined limit value so that rotation of the moving plate takes place against said first spring and second spring in such a manner that:  
       over a first angular sector the first spring is compressed up to said limit value; and  
       thereafter, over a second angular sector, only the second spring is compressed;  
       the first spring and second spring are disposed to bear at least indirectly against each other via respective ends;  
       the means suitable for limiting deformation of the first spring is an arcuate element of developed length substantially equal to the length of the first spring when compressed;  
       inertial type means for preventing rotation are interposed between the first fixed cheek-plate and the moving plate; and  
       the first fixed cheek-plate has at least one guide track for a rolling member, the side face of the moving plate having at least one cavity disposed so that in a determined relative orientation of the moving plate relative to the first fixed cheek-plate it receives the rolling member in part so as to constitute, in this position, an obstacle to rotation of the moving plate.  
     
     
       5. A method of implementing a device as presented in  claim 4 , comprising: 
       wherein the shaft is held fixed in a first position (P 1 ), rotation in a first direction (S 1 ) only being possible from said position (P 1 ), the toothed element being in a first bearing state for its teeth bearing against the ratchet of the first fixed cheek-plate;  
       wherein at least one movement of the shaft is in a first direction of rotation (S 1 ) from the first position (P 1 ) to an intermediate position contained in a first angular sector, in which intermediate position the toothed element bears against the teeth of the ratchet so that movement of the shaft in the second direction of rotation (S 2 ) is prevented;  
       wherein at least one movement of the shaft is in the first direction (S 1 ) from any position of the first angular sector towards a predefined position (P 3 ) in which:  
       the toothed element is spaced apart from the ratchet and is held apart by the abutment bearing against a complementary abutment provided on the resilient part; and  
       the stud is placed at a distance from the cam path;  
       rotary movement of the shaft in both directions of rotation (S 1 , S 2 ) being free from said position (P 3 )′ 
       wherein at least one rotary movement of the shaft is in the first direction (S 1 ) from the position (P 3 ) towards a position (P 2 ) in which the toothed element bears against the ratchet;  
       wherein at least one rotary movement of the shaft is in the first direction (S 1 ) from the position (P 2 ) to a position (P 4 ) in which:  
       the toothed element is at a distance from the ratchet and is held apart by contact between the abutment and the complementary abutment of the resilient member; and  
       the stud of the toothed element bears against the cam path; and  
       wherein at least a rotary movement of the shaft is in the first direction (S 1 ) from the position (P 4 ) to a locking position (P 5 ) in which the second toothed surface of the toothed element bears against the ratchet.  
     
     
       6. The use of a method as presented in  claim 5  to manually adjusting a seat armrest, in particular of a motor vehicle seat. 
     
     
       7. A use according to  claim 6 , in which: 
       the position (P 1 ) corresponds to the armrest being in a substantially horizontal situation;  
       the positions are adjustable tooth by tooth by rotating the shaft over the first angular sector defined by the position (P 1 ) included and the position (P 3 ) excluded, correspond to a plurality of positions in which the armrest is inclined relative to the horizontal, prevention of movement in the direction (S 2 ) enabling the armrest to be leant on in such positions;  
       the position (P 2 ) corresponds to the armrest being in a substantially vertical situation; and  
       the and positions (P 4  and P 5 ) correspond to situations in which the armrest is inclined at an angle of slightly more than 90° relative to the position (P 1 ).  
     
     
       8. A device according to  claim 1 , further comprising a resilient part mounted on the first fixed cheek plate, said resilient part including an inclining surface causing the toothed element to rock so as to prevent the moving part from turning in one direction of rotation. 
     
     
       9. A device for automatic indexed guidance of a moving part guided about an axis of rotation on a fixed part that is fixed about said axis of rotation, the device comprising: 
       a toothed element mounted to rock about a rocking axis substantially parallel to the axis of rotation;  
       a ratchet defining a plurality of abutments for the toothed element, said abutments being angularly disposed around the axis of rotation;  
       a cam path for controlling rocking movements of the toothed element about its rocking axis during rotation of the moving part; and  
       a first rigid one-piece fixed cheek-plate provided with a plurality of staged surfaces defining  
       the ratchet,  
       the cam path, and  
       at least one bearing surface guiding a moving plate in rotation about the axis of rotation, the moving plate supporting the rocking axis of the toothed element; and  
       a wherein said moving plate is in the form of a generally disk-shaped part provided with a through hole through which the shaft of the moving part passes and further comprising: 
       means enabling the moving plate to be prevented from rotating relative to said rotary shaft; and  
       wherein the moving plate is also provided on a first transverse face with a stud defining the rocking axis of the toothed element.  
     
     
       10. A device according to  claim 9 , wherein the toothed element is a substantially planar part provided with: 
       an axial hole enabling said toothed element to be mounted on the stud of the moving plate;  
       a stud projecting from said first transverse face of said toothed element, said stud forming a cam-follower finger for reading the cam path during rotation of the moving plate relative to the first fixed cheek-plate; and  
       teeth over at least a first side surface of said toothed element, said teeth being substantially complementary in shape to the teeth of the ratchet of the first fixed cheek plate.  
     
     
       11. A device according to  claim 10 , wherein the toothed element has an overall plane of symmetry (S), having two toothed surfaces disposed on said first side surface. 
     
     
       12. A device according to  claim 1 , further comprising a support part about the axis of rotation, the support part being mechanically linked to the moving plate so as to be rotated together therewith during movement of the shaft, said support part supporting a resilient return means for the toothed element. 
     
     
       13. A device according to  claim 12 , wherein the resilient return means is a flexible blade provided with an abutment, the toothed element being provided with an abutment of complementary shape with respect to said abutment of said resilient return means such that said toothed element can occupy: 
       a first state in which a first toothed surface of the toothed element bears against the ratchet of the first fixed cheek plate;  
       a second state in which the toothed element is not in contact with the ratchet, a spacing apart between said toothed element and said ratchet being conserved by reversible locking of the abutment of the toothed element against the abutment of the resilient means; and  
       a third state in which a second toothed surface of the toothed element bears against the ratchet of the first fixed cheek plate.  
     
     
       14. A device for automatic indexed guidance of a moving part guided about an axis of rotation on a fixed part that is fixed about said axis of rotation, the device comprising: 
       a toothed element mounted to rock about a rocking axis substantially parallel to the axis of rotation;  
       a ratchet defining a plurality of abutments for the toothed element, said abutments being angularly disposed around the axis of rotation;  
       a cam path for controlling rocking movements of the toothed element about its rocking axis during rotation of the moving part;  
       a first rigid one-piece fixed cheek-plate provided with a plurality of staged surfaces defining  
       the ratchet,  
       the cam path, and  
       at least one bearing surface guiding a moving plate in rotation about the axis of rotation, the moving plate supporting the rocking axis of the toothed element;  
       further comprising a support part about the axis of rotation, the support part being mechanically linked to the moving plate so as to be rotated together therewith during movement of the shaft, said support part supporting a resilient return means for the toothed element;  
       wherein the resilient return means is a flexible blade provided with an abutment, the toothed element being provided with an abutment of complementary shape with respect to said abutment of said resilient return means such that said toothed element can occupy;  
       a first state in which a first toothed surface of the toothed element bears against the ratchet of the first fixed cheek plate;  
       a second state in which the toothed element is not in contact with the ratchet, a spacing apart between the toothed element and said ratchet being conserved by reversible locking of the abutment of the toothed element against the abutment of the resilient means; and  
       a third state in which a second toothed surface of the toothed element bears against the ratchet of the first fixed cheek plate; and  
       further comprising a second fixed cheek plate provided with a through hole enabling the shaft of the moving part to pass therethrough, said second cheek plate being secured to the first fixed cheek plate so as to form a box (BO) in which there is housed a rotary assembly, said rotary assembly comprising:  
       the moving plate;  
       the toothed element that rocks on the moving plate about the axis of rotation; and  
       the support part for supporting the resilient return means.  
     
     
       15. A device according to  claim 14 , wherein the second fixed cheek plate is snap-fastened onto the first fixed cheek-plate so as to retain said rotary assembly. 
     
     
       16. A device according to  claim 14 , wherein the first and second fixed cheek-plates are fixed together, further comprising: 
       wherein the first bearing surface of the first fixed cheek plate guides the support part in rotation about the axis and prevents the support part from moving in translation;  
       wherein the second bearing surface of the first fixed cheek plate bears against at least a portion of a transverse surface of the toothed element; and  
       wherein the third bearing surface of the first fixed cheek plate guides the moving plate in rotation about the axis of rotation and prevents the moving plate from moving in translation.  
     
     
       17. A device according to  claim 14 , wherein the moving plate comprises a stud projecting from a transverse face of said moving plate placed facing the second fixed cheek plate, the stud being received in a holding bearing surface formed in the second fixed cheek-plate, the stud constituting an abutment for actuating at least one resilient member contained in said bearing surface. 
     
     
       18. A device according to  claim 17 , wherein the holding bearing surface is an annular groove about the axis of rotation. 
     
     
       19. A device according to  claim 17 , wherein the holding bearing surface contains first and second springs, the second spring being stiffer than the first spring, at least one of the first and second springs co-operating with means for limiting deformation of the first spring to a predetermined limit value so that rotation of the moving plate takes place against said springs in such a manner that: 
       over a first angular sector the first spring is compressed up to said limit value; and  
       thereafter, over a second angular sector, only the second spring is compressed.  
     
     
       20. A device according to  claim 19 , wherein said first and second springs are disposed to bear at least indirectly against each other via respective ends. 
     
     
       21. A device according to  claim 19 , wherein the means suitable for limiting deformation of the first spring is an arcuate element of length substantially equal to the length of the first spring when compressed. 
     
     
       22. A device according to  claim 14 , wherein inertial type means for preventing rotation are interposed between the first fixed cheek plate and the moving plate. 
     
     
       23. A device according to  claim 22 , wherein the first fixed cheek-plate has at least one guide track for a rolling member, the side face of the moving plate having at least one cavity disposed so that in a determined relative orientation of the moving plate relative to the first fixed cheek-plate it receives the rolling member in part so as to constitute, in this position, an obstacle to rotation of the moving plate. 
     
     
       24. A device for automatic indexed guidance of a moving part guided about an axis of rotation on a fixed part that is fixed about said axis of rotation, the device comprising: 
       a toothed element mounted to rock about a rocking axis substantially parallel to the axis of rotation;  
       a ratchet defining a plurality of abutments for the toothed element, said abutments being angularly disposed around the axis of rotation;  
       a cam path for controlling rocking movements of the toothed element about its rocking axis during rotation of the moving part;  
       a first rigid one-piece fixed cheek-plate provided with a plurality of staged surfaces defining  
       the ratchet,  
       the cam path, and  
       at least one bearing surface guiding a moving plate in rotation about the axis of rotation, the moving plate supporting the rocking axis of the toothed element; and 
       further comprising a step of holding the shaft fixed in a first position (P 1 ), rotation in a first direction (S 1 ) only being possible from said position (P 1 ), the toothed element being in a first bearing state for its teeth bearing against the ratchet of the first fixed cheek plate.  
     
     
       25. A method according to  claim 24 , further comprising at least one movement of the shaft in a first direction of rotation (S 1 ) from the first position (P 1 ) to an intermediate position contained in a first angular sector, in which intermediate position the toothed element bears against the teeth of the ratchet so that movement of the shaft in the second direction of rotation (S 2 ) is prevented. 
     
     
       26. A method according to  claim 25 , further comprising at least one movement of the shaft in the first direction (S 1 ) from any position of the first angular sector towards a predefined position (P 3 ) in which: 
       the toothed element is held apart from the ratchet by an abutment of said toothed element bearing against a complementary abutment provided on a resilient part; and  
       wherein a stud is placed at a distance from the cam path;  
       rotary movement of the shaft in both directions of rotation (S 1 , S 2 ) being free from said predefined position (P 3 ).  
     
     
       27. A method according to  claim 26 , further comprising at least one rotary movement of the shaft in the first direction (S 1 ) from the predefined position (P 3 ) towards a position (P 2 ) in which the toothed element bears against the ratchet. 
     
     
       28. A method according to  claim 27 , further comprising at least one rotary movement of the shaft in the first direction (S 1 ) from the position (P 2 ) to a position (P 4 ) in which: 
       the toothed element is at a distance from the ratchet and is held apart from said ratchet by contact between the abutment of the toothed element and the complementary abutment of the resilient part; and  
       a stud of the toothed element bears against the cam path.  
     
     
       29. A method according to  claim 28 , further comprising at least a rotary movement of the shaft in the first direction (S 1 ) from the position (P 4 ) to a locking position (P 5 ) in which a second toothed surface of the toothed element bears against the ratchet. 
     
     
       30. The method as presented in  claim 24  to manually adjust a seat armrest, in particular of a motor vehicle seat. 
     
     
       31. A method according to  claim 20 , wherein: 
       the position (P 1 ) corresponds to the seat armrest being in a substantially horizontal situation;  
       a plurality of positions which are adjustable tooth by tooth by rotating the shaft over the first angular sector defined by the position (P 1 ) included and the position (P 3 ) excluded, correspond to a plurality of positions in which the armrest is inclined relative to the horizontal, prevention of movement in the direction (S 2 ) enabling the armrest to obtain the positions in which the armrest is inclined relative to the horizontal;  
       the position (P 2 ) corresponds to the armrest being in a substantially vertical situation; and  
       the positions P 4  and P 5  correspond to positions in which the armrest is inclined at an angle of slightly more than 90° relative to the position (P 1 ).